From BiblePortal Wikipedia

Collectio [1]

is a name, in the Gallican missals, for certain forms of prayer and praise. The principal of these are the Collectio post Nomina, which follows the recitation of the names on the diptychs; the Collectio ad Pacem, which accompanies the giving of the kiss of peace; the Collectio post, Sanctus, which immediately follows the "Holy Holy, Holy," and the Collectio post Eucharistiam, after communion.